Evaluation on chickenpox disease surveillance system in Phothong Hospital, Phothong District, Ang Thong in November 2018-October 2019

Abstract

Chickenpox remains a major public health problem in Thailand, including Angthong province where the recently reported morbidity rate was higher than the national rate. In 2019, there was a chickenpox outbreak in a school in Phothong district, Ang Thong province. This study aimed to determinequantitative and qualitative attributes ofchickenpox surveillance system and provide recommendations for improvement in Phothong district, Ang Thong province.A cross-sectional study was conducted by reviewing data of chickenpox cases who lived in Phothong district, Ang Thong province and were treated in Phothong hospital during 1 November 2018 – 30 October 2019. Case definitions of chickenpox by the Bureau of Epidemiology were used. The study compared chickenpox data between those in the hospital registration and in the surveillance system to determine quantitative attributes of the surveillance including sensitivity, predictive value positive (PVP), data quality, representativeness and timeliness. Twelve health personnel involving the surveillance system were interviewed to determine qualitative attributes including simplicity, flexibility, acceptability, stability and usefulness.Of the medical records reviewed, 75 cases met chickenpox case definitions and 64 cases were reported in the surveillance system. Sixty-three cases were found in both the hospital registration and the surveillance system. The sensitivity of surveillance was 84.0% and the PVP was 98.4%. Data quality was very good and could be representative. About 96.9% of the cases were timely reported to the district surveillance center. All health personnel stated that the surveillance system was simple, flexible, acceptable, stable and useful. Chickenpox surveillance system in Phothong hospital showed good performance. However, the sensitivity of the surveillance which was not high underscored the needs for improvement if the system.